Changing a car battery
I am about to change the battery DIY.
I am thinking how I can change it and still maintain current while I do it. I was thinking if it is possible to hook jumper cables to the new battery and carefully unhook the old battery. I would then try to connect the new battery as I release the clamps. Is this possible or am I an idiot? Ok, don't answer as it could be possible and I'm still an idiot.

I don't think you would need to worry about the radio code on a W211 though. You would just have to normalise windows, steering, sunroof, what else? Not too bad this way either.

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The 'flow' is never interrupted....
This works in most multiple-battery setups (diesels, 12V and 24V systems).
It oughtta work here...

The 'flow' is never interrupted....
This works in most multiple-battery setups (diesels, 12V and 24V systems).
It oughtta work here...


The 'flow' is never interrupted....
This works in most multiple-battery setups (diesels, 12V and 24V systems).
It oughtta work here...

As mentioned before, the cigarette lighter is not active when the car is in sleep mode, so putting a 9V battery in the car would also accomplish nothing.
The best idea is to use some OK cables and keep the terminals connected that way. Jumper cables are too cumbersome. If the vehicle is asleep, it should work. Also, if the cables do become unhooked, its no big deal since the car is asleep anyway and it was worth a try.
I did not think about the second battery, but I was also under the impression that it was somehow disconnected from other electronics when the car is off. Who knows?
Good luck changing the battery. My car is just about to turn 4 years old, but I am sure the battery is just over 4 years old. I guess that I have about 1 year left on it.
Steve
Roadside Assist came out to jump. What Gullwing said is correct. I also normalized the trunk.
The manual clock showed the wrong time, but picked it up from the COMAND unit and they sync'd back up after I started the car again.
All my radio stations, bluetooth pairing, memory settings for my seats, all were just fine.



Correct 06 and later should not have 2nd battery, i was thinking of the SL which MB continued the use of the SBC (and SLR)
